Functional high-entropy alloys: promising catalysts for high-performance water splitting

Due to the urgent environmental concerns and the energy crisis, the pursuit of sustainable clean energy as an alternative to conventional fossil fuels has become a focal point for industry scholars. Electrochemical water splitting is an environment friendly and efficient method for high-purity hydrogen generation. Although platinum group metal catalysts are the most used materials for electrolytic water catalysis, their scarcity and high cost curtail their widespread application. Developing electrocatalysts with low cost and high efficiency is urgently needed, which can reduce the reaction energy barrier. High-entropy alloys (HEAs), novel materials with more than five primary elements, have unique characteristics that endow them with superior physicochemical characteristics to traditional alloys. This review presents recent developments in HEA-based electrocatalysts for water splitting. It commences with a concise elucidation of the fundamental HEA concepts, encompassing definitions, features, and fabrication methods. The discussion emphasizes theoretical guidance for selecting compositions and optimizing the properties of HEAs. Then, the analysis investigates the advantages of HEAs as water splitting electrocatalysts, elucidating their role in enhancing performance and establishing correlations between properties and activity. The article concludes with reflections and future prospects, providing insights to guide the ongoing advancement of HEA-based catalysis. State-of-the-art HEAs with outstanding water splitting performance is rationally designed, which provides a blueprint for the design of a next-generation platform for hydrogen regeneration.